The fixed focus cameras used for Advanced Driver Assistance Systems (ADAS) are subject to many external conditions that may make the lens dirty from time to time. Car manufacturers are starting to design intelligent self-cleaning cameras that can detect dirt and automatically clean the lens using air or water.
One of the difficulties encountered in the prior art is the reliable detection of foreign objects such as dust, road dirt, snow, etc., obscuring the lens while ignoring large objects that are part of the scene being viewed by the cameras.